John Brunner 
Rites of Ohe [EPUB ebook] 

‘How short a time a century really is . . .’ The speaker was Immortal Karmesin, and he had lived a thousand years. He stood, a gigantic figure against the rush of time, a permanently open channel for the infants of the galaxy to explore the deep past.He was anathema to the Phoenixes, for their creed was that of birth in death, of regeneration in destruction. And he knew that he — one man — had to unravel the Phoenix mystery, or live to watch it bring fiery death to all the planets of man . . .(First published 1963)